In recent years, professionals working with polluted sites and soils have been concerned with “emerging pollutants”, substances that are not yet regulated, although they are often already known, and which are the subject of a recent awareness of the threat they pose to humans and their environment. Analytical capacities have indeed progressed, as has knowledge of the toxicology and ecotoxicology of certain substances. Current research and regulatory developments on these “pollutants of emerging interest” concern above all PFAS, per- and polyfluoroalkyl compounds produced and widely used since the early 1950s. But what about other substances? Is it necessary to consider new compounds in the assessment of polluted sites and soils to take into account these latest advances? In 2020 and 2021, we examined this question for the Contaminated Sites section of the FOEN. By compiling a selection of information sources on the situation in Switzerland, at European and international level, we were able to give an opinion on substances or groups of substances that would deserve special attention. The study report is published on the FOEN website since April 2022.